Retrieval devices and related methods of use

ABSTRACT

According to an example of the present disclosure, a retrieval device having a contracted state and an expanded state may include at least three support members each having a lumen, a fixed proximal end, and a movable distal end, and at least two members movable relative to the support members. Each movable member may include a first end and a second end and extending distally through a lumen of a support member and proximally through a lumen of a different support member. The device may include a stop located at the second end of at least one movable member to restrict movement of the second end after moving a distance distally during movement of the retrieval device toward the expanded state.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation of U.S. Nonprovisional patentapplication Ser. No. 14/593,594, filed Jan. 9, 2015, which claimsbenefit of priority under 35 U.S.C. § 119 to U.S. Provisional PatentApplication No. 61/938,311, filed Feb. 11, 2014, and to U.S. ProvisionalPatent Application No. 61/925,952, filed Jan. 10, 2014, the entiretiesof each of which is incorporated herein by reference.

TECHNICAL FIELD

Various examples of the present disclosure relate generally to retrievaldevices and related systems and methods. More specifically, the presentdisclosure relates to devices, systems, and methods for retrievingobjects within a patient.

BACKGROUND

Retrieval devices are often used to remove organic material (e.g., bloodclots, tissue, and biological concretions such as urinary, biliary, andpancreatic stones) and inorganic material (e.g., components of a medicaldevice or other foreign matter), which may obstruct or otherwise bepresent within a patient's body cavities or passages. For example,concretions can develop in certain parts of the body, such as in thekidneys, pancreas, ureter, and gallbladder. Minimally invasive medicalprocedures are used to remove these concretions through naturalorifices, or through an incision, such as during a percutaneousnephrolithotomy (“PNCL”) procedure. Further, lithotripsy andureteroscopy, for example, are used to treat urinary calculi (e.g.,kidney stones) in the ureter of a patient.

Retrieval devices may include end effectors for manipulating objects. Anexemplary end effector may have a plurality of arms that support a frontloop that forms when the end effector is opened. The size of the frontloop may limit the size of an object that can be captured, repositioned,and/or released from the end effector. For some procedures, there may bea need to increase the size of a front loop of an end effector tofacilitate the capturing, repositioning, and/or releasing of largerobjects. It may also be desirable to have an end effector close backdown to a low-profile state to facilitate insertion and withdrawal ofthe end effector into and from a target area, and/or to capture,reposition, and/or release smaller objects. Thus, there remains a needfor retrieval devices with improved capabilities.

Further, known medical retrieval devices are complex, requiring manycomponents and labor-intensive manufacturing processes. The assembly ofsmall parts often requires visual magnification and specializedtraining. The available joining mechanisms often increase the profile ofthe medical retrieval devices beyond optimal design parameters, and areoften the weakest structural points. These drawbacks result in medicalretrieval devices that are bulky, expensive, and prone to failure.

Thus, there remains a need for improved medical retrieval devices havingreduced profiles and fewer components.

SUMMARY

Examples of the present disclosure relate to, among other things,retrieval devices and related systems and methods. Each of the examplesdisclosed herein may include one or more of the features described inconnection with any of the other disclosed examples.

According to an example of the present disclosure, a retrieval devicehaving a contracted state and an expanded state may include at leastthree support members each having a lumen, a fixed proximal end, and amovable distal end, and at least two members movable relative to thesupport members. Each movable member may include a first end and asecond end and extending distally through a lumen of a support memberand proximally through a lumen of a different support member. The devicemay further include a stop located at the second end of at least onemovable member to restrict movement of the second end after moving adistance distally during movement of the retrieval device toward theexpanded state.

The at least two movable members may include three movable members. Thestop may include a coupling securing the second ends of the at least twomovable members together. The coupling may include a tube surroundingthe second ends. Each of the movable members may include a preformedU-shaped bend located distally of the movable distal ends of the supportmembers. The U-shaped bend may urge the support members toward thecontracted state. The U-shaped bend may be located said distance fromthe movable distal end when the movable stop is abutting the fixedproximal end of the at least one support member. The movable members mayform a first stage grasper when the U-shaped bend is located saiddistance from the movable distal end. The support members may extendgenerally parallel to one another during movement of the stop distallytoward the expanded state. The device may include a sheath fixedlycoupled to the proximal end of each of the support members, the sheathextending proximally to encompass at least a portion of the movablemembers.

According to another example, a retrieval device having a contractedstate and an expanded state may include at least three support memberseach having a lumen, a fixed proximal end, and a movable distal end, andat least three members movable relative to the support members. Eachmovable member may include a first end and a second end and extendingdistally through a lumen of a support member and proximally through alumen of a different support member. The device may further include astop for the movable members, the stop including a coupling of thesecond ends of each of the movable members together at a spaced distancefrom the fixed proximal ends of the support members.

The coupling of the second ends may include securing the second ends ina tube. The stop may be located the spaced distance from the fixedproximal ends of the support members when the device is in a fullycontracted state, and the spaced distance may be reduced during movementof the device toward the expanded state. The first end may be locateddistally of the second end. Each of the movable members may include apreformed U-shaped bend located distally of the movable distal ends ofthe support members. The U-shaped bend may urge the support memberstoward the contracted state. The U-shaped bend may be located a fixeddistance from the stop and may move with the stop. The movable membersmay form a first stage grasper during initial movement toward theexpanded state. The support members may extend generally parallel to oneanother during movement of the movable stop toward the expanded state.

According to yet another example, a method for retrieving an objectusing a retrieval device is disclosed. The retrieval device may includeat least three tubular support members each having a fixed proximal endand a movable distal end. At least two members may be movable relativeto the support members. Each movable member may include a first end anda second end and extending distally through a support member andproximally through a different support member. A stop may be located atthe second end of at least one movable member. The method may includemoving the first and second ends of the movable members distally untilthe stop restricts further movement of the second ends. The method alsomay include further moving the first ends of the movable membersdistally to expand the movable distal ends of the support membersradially.

In one aspect, the present disclosure may be directed to a medicaldevice. The medical device may include a plurality of branch membershaving a proximal end and a distal end. The medical device may alsoinclude a first movable member, and a second movable member. Theplurality of branch members and the first and second movable members mayform a basket movable between a collapsed configuration and an expandedconfiguration, and the entireties of the first and second movablemembers may be configured to move distally with respect to the pluralityof branch members.

The first movable member may include a first bend disposed proximal tothe proximal ends of the plurality of branch members, and the secondmovable member may include a second bend disposed proximal to theproximal ends of the plurality of branch members. The first bend mayinclude a bend disposed at a middle portion of the first movable member;and the second bend may include a bend disposed at a middle portion ofthe second movable member. The first bend may encompass a midpoint ofthe first movable member, and the second bend may encompass a midpointof the second movable member. In the collapsed configuration, the firstand second bends may be separated from the proximal ends of theplurality of branch members by a first distance. The device may furtherinclude a drive member disposed proximally of the first and secondmovable members, wherein the first movable member has a first leg and afourth leg, the second movable member has a first leg and a fourth leg,and a distal end of the drive member is coupled to the first and fourthlegs of the first and second movable members. The first and fourth legsof the first and second movable members may each be disposed in adifferent branch member of the plurality of branch members. The drivemember may be advanced distally by the first distance to move themedical device to an intermediate configuration between the collapsedconfiguration and the expanded configuration. In the intermediateconfiguration, the first and second bends may be engaged with theproximal ends of the plurality of branch members; After the first andsecond bends are engaged with the proximal ends of the plurality ofbranch members, further distal movement of the drive member may causeeach of the first and fourth legs of the first and second movablemembers to extend distally through a respective branch member of theplurality of branch members. The first and fourth legs of the first andsecond movable members may each extend from a distal end of a respectivebranch member of the plurality of branch members to form a branch thatextends into an adjacent branch member. A proximal retraction of thedrive member while the medical device is in the expanded configurationmay cause the first and fourth legs of the first and second movablemembers to retract proximally. The first and second bends may disengagefrom the proximal ends of the plurality of branch members duringmovement of the medical device from the expanded configuration to thecollapsed configuration. The first and second bends may be engaged withthe proximal ends of the plurality of branch members when the medicaldevice is in the expanded configuration. The first movable member mayinclude a second leg and a third leg, the second movable member mayinclude a second leg and a third leg, and each of the second and thirdlegs of the first and second movable members may be disposed in adifferent branch member of the plurality of branch members. The firstand fourth legs of the first movable member and the second and thirdlegs of the first movable member may each be disposed in a differentbranch member of the plurality of branch members, and the first andfourth legs of the second movable member and the second and third legsof the second movable member may each be disposed in a different branchmember of the plurality of branch members. The proximal ends of theplurality of branch members may be coupled to one another. The devicemay include a sheath coupled to the proximal end of each of theplurality of branch members, the sheath extending proximally toencompass at least a portion of the first and second movable members.

In another aspect, the present disclosure is directed to a medicaldevice. The medical device may include a plurality of branch membershaving a proximal end and a distal end, and a first movable memberhaving a first bend disposed proximal to the proximal ends of each ofthe plurality of branch members. The medical device may include a secondmovable member having a second bend having a second bend disposedproximal to the proximal ends of each of the plurality of branchmembers. The plurality of branch members and the first and secondmovable members may form a basket movable between a collapsedconfiguration and an expanded configuration, and the first bend may beconfigured to engage with the proximal ends of a first pair of theplurality of branch members. The second bend may be configured to engagewith the proximal ends of a second pair of the plurality of branchmembers, and branch members of the first pair and second pairs of theplurality of branch members may alternate with one another.

In yet another aspect, the present disclosure is directed to a medicaldevice. The medical device may include a plurality of branch membershaving a proximal end and a distal end, and a first movable memberhaving a first bend disposed proximal to the proximal ends of each ofthe plurality of branch members, The medical device may also include asecond movable member having a second bend having a second bend disposedproximal to the proximal ends of each of the plurality of branchmembers. The plurality of branch members and the first and secondmovable members may form a basket movable between a collapsedconfiguration and an expanded configuration, and the first bend may beconfigured to engage with the proximal ends of a first pair of theplurality of branch members. The second bend may be configured to engagewith the proximal ends of a second pair of the plurality of branchmembers.

It is understood that both the foregoing general description and thefollowing detailed description are exemplary and explanatory only andare not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate examples of the presentdisclosure and together with the description, serve to explain theprinciples of the disclosure.

FIG. 1 is a side and partial view of a retrieval device including an endeffector in a retracted and contracted state, in accordance withexamples of the present disclosure.

FIG. 2 is a cross-sectional view of the retrieval device of FIG. 1, inaccordance with examples of the present disclosure.

FIG. 3 is a distal end view of the retrieval device of FIG. 1, inaccordance with examples of the present disclosure.

FIG. 4 is a perspective view of the retrieval device of FIG. 1 in anextended and expanded state, in accordance with examples of the presentdisclosure.

FIG. 5 is a distal end view of the retrieval device of FIG. 1 in theextended and expanded state, in accordance with examples of the presentdisclosure.

FIG. 6 is a full view of the retrieval device of FIG. 1 in the extendedand expanded state.

FIG. 7 is a perspective view of a medical retrieval device with a basketin an expanded configuration in accordance with an example of thepresent disclosure.

FIG. 8 is an enlarged partial perspective view of the basket of themedical device of FIG. 7.

FIG. 9 is an enlarged partial side and cross-sectional view of themedical retrieval device of FIG. 7.

FIG. 10 is a top view of the medical retrieval device of taken alongline 10-10 of FIG. 9.

FIG. 11 is a cross-sectional view of the medical retrieval device takenalong line 11-11 of FIG. 9.

FIG. 12 is a cross-sectional view of the medical retrieval device takenalong line 12-12 of FIG. 9.

FIG. 13 is an enlarged partial side and cross-sectional view of amedical retrieval device in accordance with another example of thepresent disclosure.

FIG. 14 is a top view of the medical retrieval device taken along line14-14 of FIG. 13.

FIG. 15 is a cross-sectional view of the medical retrieval device takenalong line 15-15 of FIG. 13.

FIG. 16 is a cross-sectional view of the medical retrieval device takenalong line 16-16 of FIG. 13.

DETAILED DESCRIPTION

Overview

The present disclosure is drawn to retrieval devices and related systemsand methods. Reference will now be made in detail to examples of thepresent disclosure, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or like parts.The term “distal” refers to a portion farthest away from a user whenintroducing a device into a patient. By contrast, the term “proximal”refers to a portion closest to the user when placing the device into thepatient.

EXAMPLES

FIGS. 1-5 show portions of a retrieval device 10, and FIG. 6 shown afull view of the device 10. Referring briefly to FIG. 6, the device 10includes a basket portion or grasper portion 52 including a plurality ofmovable members 18, 20, and 22, and a plurality of support members 26,28, and 30. The support members 26, 28, and 30 may be coupled to anouter sheath 12 and back to a handle assembly 90. The movable membersmay be coupled back to the handle assembly 90 through the supportmembers 26, 28, and 30 and the outer sheath 12. As explained in moredetail below, movement of an actuator 92 of the handle assembly 90 mayprovide relative movement between the movable members 26, 28, and 30 andsupport members 26, 28, and 30 to transition the grasper portion 52between an expanded state (FIG. 6) and a contracted state (FIG. 1).

Referring to FIG. 1, the outer sheath 12 of retrieval device 10 mayinclude a lumen 14 extending longitudinally therethrough. The outersheath 12 may be, for example, a hollow tube of about 1.9 French,although the dimensions may differ based on the type of procedure beingperformed with the retrieval device 10. The outer sheath 12 may be madeof a polymer material or combination of materials. A proximal portion ofthe outer sheath 12 may be made of a different material than a distalportion of the outer sheath 12. For example, the distal portion of theouter sheath 12 may be made of a material that is more flexible than thematerial of the proximal portion of the outer sheath 12.

The retrieval device 10 may also include a drive member or shaft 16. Thedrive member 16 may extend through the lumen 14 of the outer sheath 12.The drive member 16 may be elongated, and may include, for example, awire, braid, cable, shaft, and/or any other suitable drive memberconfigured to receive or transfer compression, tension, and/or torsionalforces. The drive member 16 may have any suitable cross-sectional shape,including cylindrical, elliptical, polygonal, and/or irregular. Thedrive member 16 may be made of metals, polymers, or a combination ofmaterials. It is also contemplated that the drive member 16 may have adiameter of approximately 0.0125 inches. The drive member 16 may haveother diameters, however, depending on the type of procedure beingperformed with the retrieval device 10.

The movable members of retrieval device 10 may include a first movablemember 18, a second movable member 20, and a third movable member 22.The first movable member 18 may include a first leg 18 a, a reverse orU-shaped bend 18 b, and a second leg 18 c. Similarly, the second movablemember 20 may include a first leg 20 a, a reverse or U-shaped bend 20 b,and a second leg 20 c. The third movable member 22 may also include afirst leg 22 a, a reverse or U-shaped bend 22 b, and a second leg 22 c.While three movable members 18, 20, and 22 are shown, one or moreadditional movable members may also be included.

Each of the movable members 18, 20, and 22 may be formed of any suitablematerial including, but not limited to, metals, polymers, or acombination of materials. For example, one or more of the movablemembers 18, 20, and 22 may be formed with a shape memory material, suchas Nitinol, and may be treated to possess an internal bias causing oneor more of the movable members 18, 20, and 22 to move to a preselectedposition in the absence of an urging force. For example, the U-shapedbends 18 b, 20 b, 22 b of the movable members 18, 20, and 22 maypreformed such as by heat setting into the U-shaped bend shape. Thispreformed U-shaped bend 18 b, 20 b, 22 b facilitate a clamping of thedistal ends of the support members together in the contracted state(FIG. 1). One or more of the movable members 18, 20, and 22 may be awire, braid, cable, or shaft having any suitable diameter, such as adiameter of about 0.003 inches, although other suitable diameters mayalternatively be utilized.

Each of the movable members 18, 20, and 22 may have any suitablecross-sectional shape, including cylindrical, elliptical, polygonal,and/or irregular. One or more of the movable members 18, 20, and 22 mayinclude a portion flattened, machined, extruded, drawn, and/or etchedinto a different profile than a remaining portion. One or more of themovable members 18, 20, and 22 may be slotted to allow deflection ordirectional bending. The exterior surfaces of one or more of the movablemembers 18, 20, and 22 may be roughened, notched, slotted, etched,sand-blasted, or otherwise modified to provide a better grippingsurface.

The movable members 18, 20, and 22 may be attached to the drive member16 at a first end. For example, proximal ends of the first legs 18 a, 20a, and 22 a may be attached to the distal end of the drive member 16.The attachment may be provided by one or more of a splice joint,adhesives, melting, welding, crimping, and/or any other suitableattachment mechanism. It is also contemplated that a sleeve 24 may beplaced over the proximal portions of the first legs 18 a, 20 a, and 22a, and the distal portion of the drive member 16 to secure the elementstogether. The sleeve 24 may be made of a polytetrafluoroethylene likeTEFLON. The sleeve 24 may be heat shrinkable onto the first legs 18 a,20 a, and 22 a, and the drive member 16. The sleeve 24 may have a lengthof about 11.5 cm, but it should be understood that the length and othersleeve dimensions may vary based on the type of procedure beingperformed with the retrieval device 10. The sleeve 24 may help gatherthe first legs 18 a, 20 a, and 22 a, to avoid radially outwardlymovement of the legs when pushed distally by the drive member 16, givingthe gathered portions added strength. The proximal portions of each ofthe first legs 18 a, 20 a, and 22 a may contact the proximal portions ofthe other first legs. Longitudinal axes of the proximal portions of thefirst legs 18 a, 20 a, and 22 a may be substantially parallel.

The support members of the retrieval device 10 may include a firstsupport member 26, a second support member 28, and a third supportmember 30. The support members 26, 28, and 30 may include lumens 34, 36,and 38 extending longitudinally therethrough, respectively. In oneexample, at least one of the support members 26, 28, and 30 may be atube. The support members 26, 28, and 30 may be disposedcircumferentially about the longitudinal axis of the outer sheath 12.The longitudinal axes of the support members may be disposed at equalintervals circumferentially about the longitudinal axis. It should,however, be noted that any other suitable number of support members andspacing configurations may alternatively be utilized. Each of thesupport members 26, 28, and 30 may have any suitable cross-sectionalshape, including cylindrical elliptical, polygonal, and/or irregular.One or more of the support members 26, 28, and 30 may include a portionflattened, machined, extruded, drawn, and/or etched into a differentprofile than a remaining portion. One or more of the support members 26,28, and 30 may be slotted to allow deflection or directional bending.One or more of the support members 26, 28, and 30 may have an innerdiameter of about 0.007 inches, a wall thickness of about 0.001 inches,and/or a length of about 19.5 millimeters, although other suitabledimensions may alternatively be utilized. The exterior surfaces of oneor more of the support members 26, 28, and 30 may be roughened, notched,slotted, etched, sand-blasted, or otherwise modified to provide a bettergripping surface. The support members 26, 28, and 30 may be made ofcoaxial tubes or heat shrink tubes, and made of any suitable material orcombination of materials, including a polymer such as polyimide, orpolyethylene terephthalate.

As shown in FIG. 1, the movable members 18, 20, and 22 may be extenddistally from the first, proximal end that is coupled to the drivemember 16, extend distally through a support member 26, 28, and 30 alongthe first leg 18 a, 20 a, and 22 a, form the preformed U-shaped bend 18b, 20 b, and 22 b, and extend proximally through a different supportmember 26, 28, and 30 along the second leg 18 c, 20 c, and 22 c. In thisconfiguration, the preformed U-shaped bend may confine or urge thesupport members 26, 28, and 30 toward a low profile in the contractedstate.

The movable members 18, 20, and 22, and the support members 26, 28, and30, may be heat treated simultaneously, and the material for the movablemembers 18, 20, and 22 and the support members 26, 28, and 30 may beselected such that the support members 26, 28, and 30 will not meltduring heat treatment of the movable members 18, 20, and 22. While threesupport members 26, 28, and 30 are shown, one or more additional supportmembers may be used.

Proximal portions of the support members 26, 28, and 30 may extendthrough the lumen 14, and may be covered by the outer sheath 12. Forexample, a length of about 10 millimeters of one or more of the supportmembers 26, 28, and 30 may be covered by the outer sheath 12, leaving alength of about 9.5 millimeters exposed distal to the outer sheath 12.Each of the support members 26, 28, and 30 may contact the other twosupport members. For example, each of the proximal portions of thesupport members 26, 28, and 30 may contact the proximal portions of theother two support members, such that the support members 26, 28, and 30may have a triangular arrangement around the longitudinal axis of theouter sheath 12, as shown in FIGS. 2 and 3. Longitudinal axes of thesupport members 26, 28, and 30 may form vertices of a triangle, andportions of the longitudinal axes may be parallel.

Distal portions of the support members 26, 28, and 30 may extenddistally out of the lumen 14 and away from the distal end of the outersheath 12. The distal portions may be configured to move towards andaway from the longitudinal axis of the outer sheath 12. The number ofsupport members 26, 28, and 30 may be equal to the number of movablemembers 18, 20, and 22. Alternatively, the number of support members 26,28, and 30 may be less than the movable members 18, 20, and 22. Forexample, a single movable member may form two of the movable members 18,20, and 22, for use with three support members.

Each of the three support members 26, 28, and 30 may be coupled to theouter sheath 12. For example, proximal ends of the support members 26,28, and 30 that are covered by the distal end of the outer sheath 12 maybe fixedly coupled to the distal end of the outer sheath 12 by anadhesive 13, such as an ultraviolet light curable adhesive orcyanoacrylate. Additionally or alternatively, the distal end of theouter sheath 12 may be fixedly coupled to the proximal ends of thesupport members 26, 28, and 30 by heat shrinking or by using a couplingtube glued at both ends. The coupling may keep the proximal ends of thesupport members 26, 28, and 30 stationary relative to the distal end ofouter sheath 12, while allowing the distal ends of the support members26, 28, and 30 to move relative to the distal end of the outer sheath 12and relative to one another.

The first leg 18 a may extend distally from the drive member 16, and mayenter the lumen 34 at the proximal end of the first support member 26.The first leg 18 a may extend distally through the lumen 34, and mayexit the lumen 34 at the distal end of the first support member 26.There the first leg 18 a may transition into the bend 18 b. The bend 18b may transition into the second leg 18 c. The second leg 18 c may enterthe lumen 36 at the distal end of the second support member 28. Thesecond leg 18 c may extend proximally through the lumen 36, and may exitthe lumen 36 at the proximal end of the second support member 28.

The first leg 20 a may extend distally from the drive member 16, and mayenter the lumen 36 at the proximal end of the second support member 28.The first leg 20 a may extend distally through the lumen 36, and mayexit the lumen 36 at the distal end of the second support member 28.There the first leg 20 a may transition into the bend 20 b. The bend 20b may transition into the second leg 20 c. The second leg 20 c may enterthe lumen 38 at the distal end of the third support member 30. Thesecond leg 20 c may extend proximally through the lumen 38, and may exitthe lumen 38 at the proximal end of the third support member 30.

The first leg 22 a may extend distally from the drive member 16, and mayenter the lumen 38 at the proximal end of the third support member 30.The first leg 22 a may extend distally through the lumen 38, and mayexit the lumen 38 at the distal end of the third support member 30.There the first leg 22 a may transition into the bend 22 b. The bend 22b may transition into the second leg 22 c. The second leg 22 c may enterthe lumen 34 at the distal end of the first support member 26. Thesecond leg 22 c may extend proximally through the lumen 34, and may exitthe lumen 34 at the proximal end of the first support member 26.

Alternatively, it is contemplated that the first leg 18 a may extenddistally through the first support member 26, and the second leg 18 cmay extend proximally through the third support member 30. The first leg20 a may extend distally through the second support member 28, and thesecond leg 20 c may extend proximally through the first support member26. The first leg 22 a may extend distally through the third supportmember 30, and the second leg 22 c may extend proximally through thesecond support member 28.

One or more of the proximal or second ends of the second legs 18 c, 20c, and 22 c may include a movable stop sized to abut or engage aproximal end of a support member 26, 28, and 30 after moving a distance47 distally during movement of the retrieval device toward the expandedstate. The movable stop may be formed in a number of different ways. Anexemplary movable stop is shown in FIG. 1 and includes a coupler 46 inthe form of a tube including a lumen 48 configured to receive proximalends of the second legs 18 c, 20 c, and 22 c. The second legs 18 c, 20c, and 22 c may be attached to each other within the coupler 46 andattached to the coupler 46. For example, each of the second legs 18 c,20 c, and 22 c may be attached to each other and the coupler 46 byadhesive, melting, welding, crimping, friction fit, heat-shrinking thecoupler 46, and/or any other suitable form of attachment. Portions ofthe first legs 18 a, 20 a, and 22 a may extend along the side of thecoupler 46, and may contact the exterior surface of the coupler 46. Thecoupler 46 may space portions of the first legs 18 a, 20 a, and 22 aapart from the longitudinal axis of the outer sheath 12, to help guidethe first legs 18 a, 20 a, and 22 a into the support members 26, 28, and30.

Alternatively, the movable stop could be formed by replacing the twomovable members 18 and 20 with a single moveable member having aU-shaped bend replacing the proximal ends of the second legs 18 c and 20c. In this arrangement, the U-shaped bend could form the movable stop ofthe movable members against the proximal end of the support members 26,28, and 30 during a first phase of the expansion of the retrieval device10. Further, the second leg 22 c could be coupled to the U-shaped bendto limit its travel. Alternatively, proximal U-shaped or L-shaped hooks,or any other type of obstruction (not shown) could be provided on one,two, or all of the second legs 18 c, 20 c, and 22 c to form the movablestop for abutting or engaging the support members 26, 28, and 30 andlimiting movement of the second legs 18 c, 20 c, and 22 c to thedistance 47 during the first phase of expansion of the retrieval device10.

The movable members 18, 20, and 22, and the support members 26, 28, and30, may form an end effector 50. The end effector 50 may together formthe basket or grasper portion 52. In FIGS. 1-3, the grasper portion 52is shown in the retracted and contracted state. The grasper portion 52may be moved into its retracted and contracted state by moving the drivemember 16 proximally relative to the outer sheath 12, or moving thesheath 12 distally relative to the drive member 16. Reference to“movable” members 26, 28, 30 refers to the relative movement of members26, 28, 30 in relation to other elements of the device 10, and thus itis understood that the term “movable” in movable members 26, 28, and 30includes the members being stationary during movement between thecontracted and expanded states, but movable in relation to supportmembers 26, 28, and 30 during movement between the contracted andexpanded states. In the retracted/contracted state, the bends 18 b, 20b, and 22 b may be at or adjacent to the distal ends of the supportmembers 26, 28, and 30. Distal ends of the first legs 18 a, 20 a, and 22a and the second legs 18 c, 20 c, and 22 c may be positioned within thelumens 34, 36, and 38 of the support members 26, 28, and 30. Thelongitudinal axes of the support members 26, 28, and 30 may besubstantially parallel, and both proximal and distal portions of each ofthe support members 26, 28, and 30 may be in contact with the othersupport members. Portions of the first legs 18 a, 20 a, and 22 a and thesecond legs 18 c, 20 c, and 22 c in the lumens 34, 36, and 38 may besubstantially parallel. The support members 26, 28, and 30, and/or theouter sheath 12 may help to resist bowing of the movable members 18, 20,and 22 during movement of the device between the expanded and contractedstates.

In the retracted/contracted state, the distal end of the coupler 46 maybe spaced from the proximal ends of the support members 26, 28, and 30by a distance 47. The distance 47 may be about 1 millimeter, althoughother distances may also be used. The proximal end of the coupler 46 maybe spaced from the distal end of the sleeve 24 by a distance including adistance 49. The distances 49 may total to about 16 millimeters,although other distances may also be used. In another example, distance49 may be about 11 millimeters, Smaller distances may position sleeve 24in a more proximal position relative to a flexible ureteroscope channelwhere the ureteroscope scope does not deflect. This positioning mayprevent binding of a rigid sleeve 24 within a curved portion of sheath12. However, it is also contemplated that sleeve 24 may include one ormore flexible materials. The distances 47 and 49 may vary based on theprocedure being performed with the retrieval device 10.

In FIGS. 4 and 5, the retrieval device 10 is shown with the grasperportion 52 in an extended and expanded state. In the extended andexpanded state, portions of the movable members 18, 20, and 22 may beexposed from the distal ends of the support members 26, 28, and 30 andthe outer sheath 12. Once exposed, one or more of the movable members18, 20, and 22 may move radially outwardly from the longitudinal axis ofthe outer sheath 12 due to a natural and/or applied radially outwardbiasing in one or more of the movable members 18, 20, and 22. Radiallyoutward movement of one or more of the movable members 18, 20, and 22may cause a corresponding radially outward movement of the supportmembers 26, 28, and 30.

The exposed portions of the movable members 18, 20, and 22 may formbridges 62, 64, and 66 between the distal ends of the support members26, 28, and 30. Each bridge may extend distally from the distal end of agiven support member, and may be received in the distal end of anadjacent support member. The bridges 62, 64, and 66 may be formed bydistal portions of the first legs 18 a, 20 a, and 22 a, the bends 18 b,20 b, and 22 b, and distal portions of the second legs 18 c, 20 c and 22c.

Each bridge and its corresponding two support members may form a sideloop of the grasper portion 52. Three side loops 54, 56, and 58 areshown in FIGS. 4 and 5. The bridges 62, 64, and 66 may form a front loop60 of the grasper portion 52. Materials may enter the grasper portion 52through one or more of the front loop 60 and the side loops 54, 56, and58. By adding additional movable members and support members, additionalside loops can be created.

Relative movement between drive member 16 and outer sheath 12 causesgrasper portion 52 to move to its extended and expanded state due to anatural and/or applied radially outward biasing in one or more of themovable members 18, 20, and 22. Extension and expansion of the grasperportion 52 may occur in phases. Starting from the retracted andcontracted state shown in FIG. 1, a first phase of the extension andexpansion of the grasper portion 52 may begin with movement of the drivemember 16 distally relative to the outer sheath 12 and the supportmembers 26, 28, and 30. The relative movement of the drive member 16 maycause the movable members 18, 20, and 22 and the coupler 46 to movedistally relative to the outer sheath 12. The movement of the drivemember 16, movable members 18, 20, and 22, and coupler 46 may betranslational. For example, the drive member 16, first legs 18 a, 20 a,and 22 a, bends 18 b, 20 b, and 22 b, second legs 18 c, 20 c, and 22 c,and coupler 46, may move distally relative to the outer sheath 12 andsupport members 26, 28, and 30 during the first phase. Proximal portionsof the first legs 18 a, 20 a, and 22 a and second legs 18 c, 20 c, and22 c may enter the lumens 34, 36, and 38 of the support members 26, 28,and 30 at the proximal ends of the support members 26, 28, and 30.Distal portions of the first legs 18 a, 20 a, and 22 a, bends 18 b, 20b, and 22 b, and second legs 18 c, 20 c, and 22 c may emerge from, orextend further out from, the distal ends of the support members 26, 28,and 30.

The coupler 46 forming the movable stop moves with the movable members18, 20, and 22 relative to the outer sheath 12 and support members 26,28, and 30. When the coupler 46 has traveled the distance 47 relative tothe outer sheath 12 and support members 26, 28, and 30, further distalmovement of the coupler 46 may be halted as the coupler 46 approachesthe proximal ends of the support members 26, 28, and 30. This preventsthe second legs 18 c, 20 c, and 22 c from further entering the lumens34, 36, and 38 of the support members 26, 28, and 30. At the end of thefirst phase of extension and expansion, the bends 18 b, 20 b, and 22 bmay each be spaced from distal ends of the support members 26, 28, and30 by the distance 47 because the U-shaped bends 18 b, 20 b, and 22 bare located a fixed distance from the coupler 46.

The presence of distance 47 between the support members 26, 28, and 30,and the coupler 46 facilitates the reciprocal movement of retrievaldevice 10 between the contracted and expanded states. That is, thepresence of distance 47 reduces an initial amount of force required tomove retrieval device 10 from the contracted state toward the expandedstate. As described above, movable members 18, 20, and 22 may include apreset U-shape bend 18 b, 20 b, and 22 b that serves to help clamp thedistal end of the support members 26, 28, and 30 in the contractedstate. By extending the movable members 18, 20, and 22 the distance 47,the clamping resistance of the U-shaped bends 18 b, 20 b, and 22 b onthe distal ends of the support members 26, 28, and 30 is reduced.Moreover, movement of the movable members 18, 20, and 22 away from thedistal end of the support members 26, 28, and 30 provides a greatermoment arm to overcome the bias of the U-shaped bends 18 b, 20 b, and 22b when moving the retrieval device 10 toward the expanded state.

The presence of distance 47 may also permit retrieval device 10 to forma first stage grasper by the portion of the movable members 18, 20, and22 extending distally of the support members 26, 28, and 30. This firststage grasper can capture smaller fragments within only the portion ofmovable members 18, 20, and 22 extending distally from support members26, 28, and 30 after movement of the distance 47. The distal ends ofmovable members 18, 20, and 22 may more securely capture smallerfragments than support members 26, 28, and 30 because they include amore distributed contact array or wire web than the support members 26,28, and 30. It is noted that during the first phase movement of themovable members 18, 20, and 22, the support members extend generallyparallel to one another. As understood, the word “generally” as usedherein means mainly, and if more specificity is required, means a rangeof plus or minus eight percent of the relevant value.

A second phase of the extension and expansion of the grasper portion 52may begin after distal movement of the coupler 46 has been halted.During the second phase, further distal movement of the drive member 16relative to the outer sheath 12 and support members 26, 28, and 30 maydrive distal movement of the first legs 18 a, 20 a, and 22 a relative tothe outer sheath 12 and support members 26, 28, and 30. During thesecond phase, the second legs 18 c, 20 c, and 22 c may remain stationaryrelative to the support members 26, 28, and 30. The first legs 18 a, 20a, and 22 a may be increasingly exposed from the distal ends of thesupport members 26, 28, and 30, thereby increasing the lengths of thebridges 62, 64, and 66. Distal portions of the movable members 18, 20,and 22, and the support members 26, 28, and 30, may expand radiallyoutwardly. The front loop 60 and the side loops 54, 56, and 58 may alsoexpand in size.

Extension and expansion in the second phase may continue over thedistance 49. Once the first legs 18 a, 20 a, and 22 a have traveled thedistance 49, distal movement of the drive member 16 may halt. Distalmovement of the drive member 16 may be halted, for example, by a stopformed in the handle assembly described in FIG. 6.

Moving the grasper portion 52 back to the retracted and contracted statemay be accomplished by moving the drive member 16 proximally relative tothe outer sheath 12 and support members 26, 28, and 30. Movement fromthe extended and expanded state to the retracted and contracted statemay also occur in phases. A first phase of the retraction andcontraction of the grasper portion 52 may begin with the drive member 16moving proximally relative to the outer sheath 12. This may cause thefirst legs 18 a, 20 a, and 22 a to move proximally relative to the outersheath 12 and support members 26, 28, and 30. Distal portions of thefirst legs 18 a, 20 a, and 22 a may enter the lumens 34, 36, and 38 atthe distal ends of the support members 26, 28 and 30. The second legs 18c, 20 c, and 22 c, and the coupler 46 may remain stationary relative tothe support members 26, 28, and 30. The lengths of the bridges 62, 64,and 66 may decrease. The first legs 18 a, 20 a, and 22 a, second legs 18c, 20 c, and 22 c, and support members 26, 28, and 30 may move radiallyinwardly. Thus, the front loop 60 and the side loops 54, 56, and 58 maydecrease in size.

The first phase of the retraction and contraction of the grasper portion52 may take place over the distance 49. Once the distance 49 has beencovered, a second phase of the retraction and contraction may take placewith continued movement of the drive member 16 proximally relative tothe outer sheath 12 and the support members 26, 28, and 30. Thecontinued movement may cause the movable members 18, 20, and 22 and thecoupler 46 to move distally relative to the outer sheath 12 and supportmembers 26, 28, and 30. The movement of the drive member 16, movablemembers 18, 20, and 22, and coupler 46 may be translational. Forexample, the drive member 16, first legs 18 a, 20 a, and 22 a, bends 18b, 20 b, and 22 b, second legs 18 c, 20 c, and 22 c, and coupler 46, maymove proximally relative to the outer sheath 12 and support members 26,28, and 30 during the second phase. Proximal portions of the first legs18 a, 20 a, and 22 a and second legs 18 c, 20 c, and 22 c may exit thelumens 34, 36, and 38 of the support members 26, 28, and 30 at theproximal ends of the support members 26, 28, and 30. Distal portions ofthe first legs 18 a, 20 a, and 22 a, bends 18 b, 20 b, and 22 b, andsecond legs 18 c, 20 c, and 22 c may enter into, or move further past,the distal ends of the support members 26, 28, and 30. The lengths ofthe bridges 62, 64, and 66 may decrease as the exposed lengths of themovable members 18, 20, and 22 decrease. As the bridges 62, 64, and 66shrink, distal portions of the movable members 18, 20, and 22, and thesupport members 26, 28, and 30, may contract radially inwardly towardthe longitudinal axis of the outer sheath 22. The front loop 60 and sideloops 54, 56, and 58 may also shrink in size.

The coupler 46 may move with the movable members 18, 20, and 22 relativeto the outer sheath 12 and support members 26, 28, and 30. When thecoupler 46 has traveled the distance 47 relative to the outer sheath 12and support members 26, 28, and 30, further proximal movement of thecoupler 46 may be halted by operation of the handle assembly 90, such asa stop formed in the handle assembly 90 of FIG. 6. At the end of thesecond phase of retraction and contraction, the state shown in FIG. 1 isattained. As noted above, in this contracted state, movable members 18,20, and 22 may include preset U-shape bends 18 b, 20 b, and 22 b locatedadjacent the distal ends of the support members 26, 28, and 30 thatserve to help clamp the distal end of the support members 26, 28, and 30in the contracted state.

FIG. 6 illustrates the handle assembly 90 disposed at the proximal end86 of the retrieval device 10. Handle assembly 90 may include anactuator 92 such as, e.g., a sliding mechanism, rotating mechanism,pushing mechanism, or the like. Actuator 92 may be coupled to outersheath 12 and include internal stops for limiting movement of the outersheath 12 relative to the movable members 18, 20, and 22. The drivemember 16 may be fixed to a proximal end of the handle assembly 90. Itis understood that the handle assembly may be formed in any conventionalmanner to control the movement of movable members 18, 20, and 22relative to the outer sheath 12 and support members 26, 28, and 30 asdescribed above. As noted above, handle assembly 90 may include one ormore internal or external stops to limit movement of the movable members18, 20, and 22.

As shown in FIGS. 7 and 8, a medical device 100 according to an exampleof the present disclosure may extend from a proximal end 102 toward adistal end 104. Medical device 100 may include a handle 126 disposed atproximal end 102. Handle 126 may include an actuator 130 such as, e.g.,a sliding mechanism, rotating mechanism, pushing mechanism, or the like.Actuator 130 may be coupled to a drive member 128 (shown only in FIG. 8)in any conventional manner to control the movement of a basket 106disposed at distal end 104 of medical device 100. Drive member 128 maybe a filament, braided wire, rope, rod, or other suitable drive member.

Basket 106 may include a plurality of branch members 108 and movablemembers 112 and 113 passing through the branch members 108 as will beexplained in more detail below. Basket 106 may be configured toreciprocally move between an expanded configuration (shown in FIGS. 7and 8) and a collapsed configuration (shown in FIGS. 9-12). A sheath 118(shown in FIGS. 8 and 9) may be fixedly disposed around the proximalends of branch members 108. Distal portions of the branch members 108may extend distally out of the sheath 118. The distal portions of branchmembers 108 may be configured to move towards and away from thelongitudinal axis of the sheath 118. In some examples, sheath 118 mayextend proximally to encompass at least a portion of movable members112, 113. The proximal end of sheath 118 may be coupled to a strainrelief portion 124. Strain relief portion 124 may be configured toprovide support between handle 126 and a proximal end of sheath 118.Thus, the proximal ends of sheath 118 and strain relief portion 124 maybe coupled to handle 126.

Each of the movable members 112, 113 may have any suitablecross-sectional shape, including cylindrical, elliptical, polygonal,and/or irregular. One or more of the movable members 112, 113 mayinclude a portion flattened, machined, extruded, drawn, and/or etchedinto a different profile than a remaining portion. One or more of themovable members 112, 113 may be slotted to allow deflection ordirectional bending. The exterior surfaces of one or more of the movablemembers 112, 113 may be roughened, notched, slotted, etched,sand-blasted, or otherwise modified to provide a better grippingsurface. One or more of the movable members 112, 113 may be formed ofany suitable material including, but not limited to, metals, polymers,or a combination of materials. In one example, one or more of themovable members 112, 113 may include a metal wire coated with a polymer.In an alternative example, one or more of the movable members 112, 113may be formed from two or more metals that are co-drawn together. In oneexample, one or more of the movable members 112, 113 may be formed witha shape memory material, such as, e.g., Nitinol wires having a diameterof about 0.003″.

The movable members 112, 113 may be attached to the drive member 128.For example, proximal ends of a first leg 112 a, a fourth leg 112 g, afirst leg 113 a, and a fourth leg 113 g may be attached to the distalend of the drive member 128. The attachment may be provided by one ormore of a splice joint, adhesives, melting, welding, crimping, and/orany other suitable attachment mechanism.

Referring to FIG. 8, the longitudinal axes of the branch members 108 maybe disposed at equal intervals circumferentially about longitudinal axis110. It should, however, be noted that any other suitable number ofbranch members and spacing configurations may alternatively be utilized.In some examples, branch members 108 may be hollow tubes configured toreceive the movable members 112, 113 therethrough. In some examples, theproximal ends of branch members 108 may be coupled to one another. Eachof the branch members 108 may have any suitable cross-sectional shape,including cylindrical, elliptical, polygonal, and/or irregular. One ormore of the branch members 108 may include a portion flattened,machined, extruded, drawn, and/or etched into a different profile than aremaining portion. One or more of the branch members 108 may be slottedto facilitate deflection or directional bending. One or more of thebranch members 108 may have an inner diameter of about 0.007 inches, awall thickness of about 0.001 inches, and/or a length of about 19.5millimeters, although other suitable dimensions may alternatively beutilized. The exterior surfaces of one or more of the branch members 108may be roughened, notched, slotted, etched, sand-blasted, or otherwisemodified to provide a better gripping surface. The branch members 108may be made of any suitable material, including a polymer such aspolyimide, or polyethylene terephthalate.

In some examples, branch members 108 and/or movable members 112, 113 maybe biased (e.g., pre-bent or curved) such that in the expandedconfiguration, branch members 108 and/or movable members 112, 113 arenaturally urged radially outward from longitudinal axis 110 of medicaldevice 100. Alternatively, branch members 108 and/or movable members112, 113 may be unbiased, in that their neutral position is straight andparallel with the longitudinal axis 110 of medical device 100.

Exposed portions of the movable members 112, 113, that extend distallyfrom a given branch member 108, may form bridges 112 h, 112 i, 113 h,and 113 i between the distal ends of the branch members 108. That is,each bridge 112 h, 112 i, 113 h, and 113 i may extend distally from thedistal end of a given branch member 108, and may be received in thedistal end of an adjacent branch member 108. The bridges 112 h, 112 i,113 h, and 113 i may be formed by distal portions of first leg 112 a,fourth leg 112 g, first leg 113 a, and fourth leg 113 g, and bends 112b, 112 f, 113 b, and 113 f (shown in FIG. 10). Materials may enterbasket 106 via one of a plurality of side openings 114 defined byadjacent branch members 108, or via a distal opening 116 defined byadjacent bridges.

Branch members 108 may be secured within sheath 118 by an adhesive, suchas, e.g., an ultraviolet light curable adhesive, glue, or cyanoacrylate.It should be noted, however, that any other suitable adhesive, orsecuring mechanism may alternatively be utilized. Sheath 118 may beformed of a polymer, such as, e.g., polyimide or polyethyleneterephthalate, among others. Adhesive may be applied around the proximalends of branch members 108 to secure them circumferentially withinsheath 118. Alternatively, sheath 118 may be a heat shrink disposedaround the proximal ends of branch members 108. The coupling may keepthe proximal ends of the branch members 108 stationary relative to thedistal end of sheath 118, while allowing the distal ends of the branchmembers 108 to move relative to the distal end of the sheath 118 andrelative to one another.

Referring to FIGS. 9-12, first leg 112 a of movable member 112 mayextend distally from the drive member 128, and may enter the proximalend of a branch member 108 b. The first leg 112 a may extend distallythrough branch member 108 b, and may exit the distal end of the branchmember 108 b. There, the first leg 112 a may transition into a bend 112b. The bend 112 b may transition into a second leg 112 c. The second leg112 c may enter the distal end of a branch member 108 a. The second leg112 c may extend proximally through branch member 108 a, and may exitthe proximal end of branch member 108 a. There, the second leg 112 c maytransition into a bend 112 d that encompasses a middle portion(including the midpoint) of movable member 112. Bend 112 d maytransition into a third leg 112 e. The third leg 112 e may enter theproximal end of a branch member 108 d. The third leg 112 e may extenddistally through branch member 108 d, and may exit the distal end ofbranch member 108 d. There, third leg 112 e may transition into bend 112f. Bend 112 f may transition into fourth leg 112 g. The fourth leg 112 gmay extend proximally through branch member 108 a, and may exit theproximal end of branch member 108 a. There, fourth leg 112 g may becoupled to drive member 128.

First leg 113 a of movable member 113 may extend distally from the drivemember 128, and may enter the proximal end of branch member 108 d. Thefirst leg 113 a may extend distally through branch member 108 d, and mayexit the distal end of the branch member 108 d. There, the first leg 113a may transition into a bend 113 b. The bend 113 b may transition into asecond leg 113 c. The second leg 113 c may enter the distal end of abranch member 108 c. The second leg 113 c may extend proximally throughbranch member 108 c, and may exit the proximal end of branch member 108c. There, the second leg 113 c may transition into a bend 113 d thatencompasses a middle portion (including the midpoint) of movable member113. Bend 113 d may transition into a third leg 113 e. The third leg 113e may enter the proximal end of branch member 108 b. The third leg 113 emay extend distally through branch member 108 b, and may exit the distalend of branch member 108 b. There, third leg 113 e may transition intobend 113 f. Bend 113 f may transition into fourth leg 113 g. The fourthleg 113 g may extend proximally through branch member 108 c, and mayexit the proximal end of branch member 108 c. There, fourth leg 113 gmay be coupled to drive member 128.

Thus, in the example shown in FIGS. 7-12, branch members 108 a and 108 cmay represent an alternating pair of branch members each having two legsof a respective same movable member disposed therethrough (e.g., legs112 c and 112 g of movable member 112 may be disposed through branchmember 108 a, while legs 113 c and 113 g of movable member 113 may bedisposed through branch member 108 c). Branch members 108 b and 108 dmay represent an alternating pair of branch members each having aportion of two different movable members disposed therethrough (e.g.,leg 112 a of movable member 112 and leg 113 e of movable member 113 maybe disposed through branch member 108 b, while leg 112 e of movablemember 112 and leg 113 a of movable member 113 may be disposed throughbranch member 108 d).

To move medical device 100 from the collapsed configuration of FIGS.9-12 to, e.g., the expanded configuration shown in FIGS. 7 and 8, drivemember 128 (referring to FIG. 8) may be moved distally to direct movablemembers 112 and 113 distally. Initially, the entireties of both movablemembers 112 and 113 move distally and longitudinally (and with respectto branch members 108 a-d) by a distance 450 (shown only in FIG. 9). Thedistance 450 may be determined by the distance between the proximal endsof branch members 108 a-d and bends 112 d and 113 d. That is, theentireties of movable members 112, 113 may move longitudinally untilmedical device 100 reaches an intermediate configuration when bend 112 dengages the proximal ends of branch members 108 a and 108 d, and bend113 d engages the proximal ends of branch members 108 b and 108 c. Whilebends 112 d and 113 d are engaged with the proximal ends of branchmembers 108 a-d, bends 112 d and 113 d may have moved distally by adistance 450 such that no distance is disposed between bends 112 d and113 d and the proximal ends of branch members 108 a-d. As movablemembers 112 and 113 move distally by the distance 450, bridges 112 h,113 i, 113 h, and 112 i (referring to FIG. 8) extend from the distalends of branch members 108 a, 108 b, 108 c, and 108 d, respectively, bythe distance 450. Once bends 112 d and 113 d are engaged with theproximal ends of branch members 108 a-d, drive member 128 may be moveddistally by an additional distance 460, displacing bridges 112 h, 113 i,113 h, and 112 i distally by the additional distance 460. Thus, in afully expanded configuration, bridges 112 h, 113 i, 113 h, and 112 i maybe displaced from the distal ends of branch members 108 a, 108 b, 108 c,and 108 d by a distance equal to the sum of twice the distance of 450,and distance 460. Distance 460 may represent the longitudinal distancebetween bends 112 d and 113 d and a distalmost point along movablemembers 112 and 113 where legs 112 a, 112 g, 113 a, and 113 g are unableto separate from one another.

Once bends 112 d and 113 d are engaged with the proximal ends of branchmembers 108 a-d, legs 112 c, 113 e, 113 c, and 112 e may be fixed withrespect to branch members 108 a, 108 b, 108 c, and 108 d, respectively.That is, the legs 112 c, 113 e, 113 c, and 112 e may move in the samemanner (i.e., coextensively) with respective branch members 108 a, 108b, 108 c, and 108 d when bends 112 d and 113 d are engaged with theproximal ends of branch members 108 a-d. Drive member 128 may be movedproximally to return medical device 100 to the collapsed configuration.

Movable members may be routed through various branch members in anysuitable configuration such that a distance (e.g., 450) is disposedbetween proximal bends (e.g., 112 d and 113 d) of the movable members,and the proximal ends of the branch members. For example, a medicaldevice 800 may include movable members 812 and 813 that are routedthrough branch members 808 a-d in the example shown by FIGS. 13-16.Movable members 812 and 813, and branch members 808 a-d, may besubstantially similar to movable members 112 and 113, and branch members108 a-d, respectively.

Referring to FIGS. 13-16, first leg 812 a of movable member 812 mayextend distally from the drive member 128, and may enter the proximalend of a branch member 808 a. The first leg 812 a may extend distallythrough branch member 808 a, and may exit the distal end of the branchmember 808 a. There, the first leg 812 a may transition into a bend 812b. The bend 112 b may transition into a second leg 812 c. The second leg812 c may enter the distal end of a branch member 808 d. The second leg812 c may extend proximally through branch member 808 d, and may exitthe proximal end of branch member 808 d. There, the second leg 812 c maytransition into a bend 812 d that encompasses a middle portion(including the midpoint) of movable member 812. Bend 812 d maytransition into a third leg 812 e. The third leg 812 e may enter theproximal end of a branch member 808 b. The third leg 812 e may extenddistally through branch member 808 b, and may exit the distal end ofbranch member 808 b. There, third leg 812 e may transition into bend 812f. Bend 812 f may transition into fourth leg 812 g. The fourth leg 812 gmay extend proximally through a branch member 808 c, and may exit theproximal end of branch member 808 c. There, fourth leg 812 g may becoupled to drive member 128.

First leg 813 a of movable member 813 may extend distally from the drivemember 128, and may enter the proximal end of branch member 808 b. Thefirst leg 813 a may extend distally through branch member 808 b, and mayexit the distal end of the branch member 808 b. There, the first leg 813a may transition into a bend 813 b. The bend 813 b may transition into asecond leg 813 c. The second leg 813 c may enter the distal end ofbranch member 808 a. The second leg 813 c may extend proximally throughbranch member 808 a, and may exit the proximal end of branch member 808a. There, the second leg 813 c may transition into a bend 813 d thatencompasses a middle portion (including the midpoint) of movable member813. Bend 813 d may transition into a third leg 813 e. The third leg 813e may enter the proximal end of branch member 808 c. The third leg 813 emay extend distally through branch member 808 c, and may exit the distalend of branch member 808 c. There, third leg 813 e may transition intobend 813 f. Bend 813 f may transition into fourth leg 813 g. The fourthleg 813 g may extend proximally through branch member 808 d, and mayexit the proximal end of branch member 808 d. There, fourth leg 813 gmay be coupled to drive member 128.

Thus, in the example shown in FIGS. 13-16, each of branch members 808a-d may have a portion of two different movable members disposedtherethrough (e.g., one of each movable members 812 and 813 may bedisposed through each branch member 808 a-d).

Medical device 800 may be opened and closed in a substantially similarmanner as medical device 100 described with reference to FIGS. 7-12. Forexample, a distance 850 (shown only in FIG. 13, substantially similar todistance 450) may be determined by the distance between the proximalends of branch members 808 a-d and bends 812 d and 813 d. Thus, theentireties of movable members 812, 813 may move longitudinally, and withrespect to branch members 808 a-d. As movable members 812 and 813 aremoved distally by distances 850 and 860, bridges of medical device 800(not shown, but substantially similar to bridges 112 h, 112 i, 113 h,and 113 i of FIG. 7) may extend distally from the distal ends of branchmembers 808 a-d by a distance equal to the sum of twice the distance850, and distance 860.

The presence of distance 450 between the proximal ends or branch members108 a-d and bends 112 d and 113 d may facilitate the reciprocal movementof medical device 100 between the collapsed and expanded configurations.That is, the presence of distance 450 may reduce an initial amount offorce required move medical device 100 from the collapsed configuration.In some examples, distance 450 may thus allow basket 106 to open withgreater ease by increasing the distance that movable members 112 extenddistally from branch members 108, thereby reducing the clamping force ofthe distal ends of movable members 112. The reduction in clamping forcemay facilitate the outward radial expansion of movable members 112. Thepresence of distance 450 may also permit medical device 100 to capturesmaller fragments within only the portion of movable members 112extending distally from branch members 108. The distal ends of movablemembers 112 may more securely capture smaller fragments than branchmembers 108 alone. Distance 850 may function in a similar manner formedical device 800.

The disclosed retrieval devices may be utilized in any suitableapplication requiring the capture and removal of materials from thebody. Any aspect set forth in any example may be used with any otherexample set forth herein. The devices may be used in any suitablemedical procedure, may be advanced through any suitable body lumen andbody cavity, and may be used to remove material from any suitable bodyportion. For example, the devices described herein may be used throughany natural body lumen or tract, including those accessed orally,vaginally, rectally, nasally, urethrally, or through incisions in anysuitable tissue.

The disclosed devices may be configured to capture fragments havingdimensions of about 3 French or smaller. In some examples, the disclosedmedical devices may be able to capture and release smaller stones havingdiameters from 1 millimeter to 12 millimeters. In some examples, a usermay want to reposition larger stones from the lower calyx to the uppercalyx of the kidney to be broken with a laser before removing themthrough a small diameter of the ureter. The stones may be removed infront of a scope, as opposed to through scope channel to prevent damageto a scope channel. When stones are removed, both an endoscope and theretrieval device may be removed from the human body. In some examples, aguide sheath for a ureteroscope may be used to guide the ureteroscopeand retrieval device back to a previous position or to a new position tocapture additional stones, and protect a ureter wall during stoneremoval. While moving from the extended and expanded state to theretracted and contracted state, retrieval devices of the presentdisclosure may ligate larger stones and capture smaller stones withinthe grasper portion 52.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the disclosed systems andprocesses without departing from the scope of the disclosure. Forexample, the retrieval device disclosed could include more than threesupport members, such as four or five support members, and an equalnumber or less movable members. Other examples of the disclosure will beapparent to those skilled in the art from consideration of thespecification and practice of the features disclosed herein. It isintended that the specification and examples be considered as exemplaryonly.

I claim:
 1. A retrieval device, comprising: a grasper movable between afully contracted state and an expanded state, the grasper including aplurality of movable members and a plurality of support members,wherein, the grasper moves from the fully contracted state to theexpanded state only after: entireties of each of the plurality ofmovable members move distally by a distance relative to each of theplurality of support members while the support members remain in thesame position, wherein the support members are tubes.
 2. The retrievaldevice of claim 1, wherein, after each of the plurality of movablemembers has moved distally by the distance, further distal movement offirst ends of each of the plurality of movable members causes distalends of the support members to bow radially outward from a centrallongitudinal axis of the grasper.
 3. The retrieval device of claim 2,wherein the further distal movement of the first ends of each of theplurality of movable members causes portions of each of the plurality ofmovable members to bow radially outward from the central longitudinalaxis of the grasper.
 4. The retrieval device of claim 1, furtherincluding a stop, wherein: second ends of the plurality of movablemembers are coupled to the stop; and the stop is configured to restrictmovement of the second ends of the plurality of movable members aftermoving the distance distally.
 5. The retrieval device of claim 4,wherein the stop is located proximal to proximal ends of each of thesupport members.
 6. A retrieval device, comprising: a grasper movablebetween a fully contracted state and an expanded state, the grasperincluding a plurality of movable members and a plurality of supportmembers, wherein, the grasper moves from the fully contracted state tothe expanded state only after: entireties of each of the plurality ofmovable members move distally by a distance relative to each of theplurality of support members while the support members remain in thesame position, the retrieval device further including a stop, wherein:second ends of the plurality of movable members are coupled to the stop;and the stop is configured to restrict movement of the second ends ofthe plurality of movable members after moving the distance distally,wherein the stop includes a coupling securing the second ends of atleast two movable members together, and the coupling includes a tubesurrounding the second ends.
 7. A retrieval device, comprising: agrasper movable between a fully contracted state and an expanded state,the grasper including a plurality of movable members and a plurality ofsupport members, wherein, the grasper moves from the fully contractedstate to the expanded state only after: entireties of each of theplurality of movable members move distally by a distance relative toeach of the plurality of support members while the support membersremain in the same position, the retrieval device further including astop, wherein: second ends of the plurality of movable members arecoupled to the stop; and the stop is configured to restrict movement ofthe second ends of the plurality of movable members after moving thedistance distally, wherein in the expanded state, portions of theplurality of support members and portions of the plurality of movablemembers move radially outward relative to a central longitudinal axis ofthe retrieval device only after: the stop has moved the distancedistally, and after the stop has moved the distance distally, first endsof the movable members are moved further distally.
 8. A retrievaldevice, comprising: a grasper movable between a fully contracted stateand an expanded state, the grasper including a plurality of movablemembers and a plurality of support members, wherein, the grasper movesfrom the fully contracted state to the expanded state only after:entireties of each of the plurality of movable members move distally bya distance relative to each of the plurality of support members whilethe support members remain in the same position, wherein each of theplurality of support members includes a lumen, a fixed proximal end, anda movable distal end.
 9. A retrieval device, comprising: a graspermovable between a fully contracted state and an expanded state, thegrasper including a plurality of movable members and a plurality ofsupport members, wherein, the grasper moves from the fully contractedstate to the expanded state only after: entireties of each of theplurality of movable members move distally by a distance relative toeach of the plurality of support members while the support membersremain in the same position, wherein each movable member extendsdistally through a lumen of a support member and proximally through alumen of a different support member.
 10. A retrieval device, comprising:a grasper movable between a fully contracted state and an expandedstate, the grasper including a plurality of movable members and aplurality of support members, wherein, the grasper moves from the fullycontracted state to the expanded state only after: entireties of each ofthe plurality of movable members move distally by a distance relative toeach of the plurality of support members while the support membersremain in the same position, wherein the movable members are wires. 11.A retrieval device, comprising: a grasper movable between a fullycontracted state and an expanded state, the grasper including aplurality of movable members and a plurality of support members,wherein, the grasper moves from the fully contracted state to theexpanded state only after: entireties of each of the plurality ofmovable members move distally by a distance relative to each of theplurality of support members while the support members remain in thesame position, wherein the plurality of movable members includes exactlythree movable members.
 12. The retrieval device of claim 11, wherein theplurality of support members includes exactly three support members. 13.A retrieval device, comprising: a grasper movable between a fullycontracted state and an expanded state, the grasper including aplurality of movable members and a plurality of support members,wherein, the grasper moves from the fully contracted state to theexpanded state only after: entireties of each of the plurality ofmovable members move distally by a distance relative to each of theplurality of support members while the support members remain in thesame position, wherein each of the movable members includes a preformedU-shaped bend located distally of movable distal ends of the supportmembers, and the U-shaped bend urges the grasper toward the fullycontracted state.
 14. A retrieval device, comprising: a grasper movablebetween a fully contracted state and an expanded state, the grasperincluding a plurality of movable members and a plurality of supportmembers, wherein, the grasper moves from the fully contracted state tothe expanded state only after: entireties of each of the plurality ofmovable members move distally by a distance relative to each of theplurality of support members while the support members remain in thesame position, wherein the support members extend generally parallel toone another during initial movement of the entireties of each of theplurality of movable members distally by the distance.
 15. A retrievaldevice, comprising, a grasper movable between a fully contracted stateand an expanded state, the grasper including a plurality of movablemembers and a plurality of support members, wherein, the grasper movesfrom the fully contracted state to the expanded state only after:entireties of each of the plurality of movable members move distally bya distance relative to each of the plurality of support members whilethe support members remain in the same position, and the retrievaldevice further including a sheath fixedly coupled to a proximal end ofeach of the support members, the sheath extending proximally toencompass at least a portion of the movable members.
 16. A retrievaldevice, comprising: at least two tubes each having a lumen, a fixedproximal end, and a movable distal end; at least two wires movablerelative to the tubes, each wire including a first end and a second end,and extending distally through a lumen of a tube and proximally througha lumen of a different tube; an actuator coupled to the first ends ofeach of the wires, the actuator configured to move the first ends of thewires proximally and distally relative to the at least two tubes; andwhile the retrieval device is in a contracted state, initial movement ofthe actuator distally also moves the second ends of the wires distallyuntil the second ends of the wires are prevented from moving furtherdistally; and after the second ends are prevented from moving furtherdistally, further distal movement of the actuator causes the movabledistal ends of the at least two tubes, and the at least two wires tomove radially outward to an expanded state of the retrieval device. 17.The retrieval device of claim 16, wherein the second ends of the wiresare located a spaced distance from the fixed proximal ends of the tubeswhen the device is in a fully contracted state, and the spaced distanceis reduced during movement of the device toward the expanded state. 18.A retrieval device, comprising: a grasper movable between a fullycontracted state and an expanded state, the grasper including aplurality of movable members, wherein, the grasper moves from the fullycontracted state to the expanded state only after: entireties of each ofthe plurality of movable members move distally by a distance before anyradial expansion of any portion of the plurality of movable members,wherein the grasper further includes a plurality of support members,wherein a number of the plurality of movable members is equal to anumber of the plurality of movable members in the grasper, and eachmovable member extends distally through a lumen of a support member andproximally through a lumen of a different support member.
 19. Theretrieval device of claim 18, wherein the support members are tubes. 20.The retrieval device of claim 18, wherein the movable members are wires.